Cooling apparatus

ABSTRACT

A cooling apparatus includes a cold plate with a first refrigerant channel through which refrigerant flows, and a pump to circulate the refrigerant. The cold plate includes a bottom wall and an upper wall. A lower surface of the bottom wall is in contact with a heating element. The upper wall is located in contact with the bottom wall. A lower surface of the upper wall and an upper surface of the pump directly oppose each other. A lower surface of the pump is exposed to an outside of the cooling apparatus.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a Continuation of U.S. application Ser. No.16/689,181, filed on Nov. 20, 2019, and claims priority under 35 U.S.C.§ 119 to Japanese Application No. 2018-248650 filed on Dec. 28, 2018,the entire contents of which are hereby incorporated herein byreference.

1. FIELD OF THE INVENTION

The present disclosure relates to a cooling apparatus.

2. BACKGROUND

A known electronic-component cooling apparatus includes a heatsink, aradiator, and an electric pump.

For example, the heatsink of a known electronic-component coolingapparatus has an electronic-component mount surface to which anelectronic component to be cooled is mounted and a refrigerant channelthrough which liquid refrigerant flows. The radiator has a liquidchannel through which the refrigerant flows. The liquid channel isair-cooled to cool the refrigerant. The electric pump provides migrationenergy to the refrigerant to circulate the refrigerant between theheatsink and the radiator.

However, the heatsink, the radiator, and the electric pump of the knowncooling apparatus are connected to each other with pipes, which resultsin an increase in the size of the entire cooling apparatus.

SUMMARY

An example embodiment of a cooling apparatus of the present disclosureincludes a cold plate with a first refrigerant channel through whichrefrigerant flows, and a pump to circulate the refrigerant. The coldplate includes a bottom wall and an upper wall. A lower surface of thebottom wall is in contact with a heating element. The upper wall islocated in contact with the bottom wall. A lower surface of the upperwall and an upper surface of the pump directly oppose each other. Alower surface of the pump is exposed to an outside of the coolingapparatus.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the example embodiments with referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a cooling apparatus according to anexample embodiment of the present disclosure.

FIG. 2 is a bottom perspective view of a cooling apparatus according toan example embodiment of the present disclosure.

FIG. 3 is a top view of the cooling apparatus according to an exampleembodiment of the present disclosure.

FIG. 4 is a sectional perspective view taken along line A-A in FIG. 3.

FIG. 5 is a sectional view taken along line B-B in FIG. 3.

FIG. 6 is a bottom view of an upper wall of the cold plate of a coolingapparatus according to an example embodiment of the present disclosure.

FIG. 7 is a top view of a bottom wall of the cold plate of the coolingapparatus according to an example embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments of the present disclosure are described hereinbelowwith reference to the drawings. In the application concerned, the side,where a radiator 20 is disposed, of a cold plate 10 is referred to as an“upside”, and the side opposite from the side where the radiator 20 isdisposed is referred to as a “downside”. In the application, a directionin which the radiator 20 is disposed on the cold plate 10 is referred toas an “up-down direction”, and a direction perpendicular to the “up-downdirection” is referred to as a “horizontal direction” to describe theshapes of the components and the positional relationships thereof.However, these definitions of the up-down direction and the horizontaldirection are merely for the convenience of description and are notintended to limit the directions in manufacturing and using the coolingapparatus 1 according to the present disclosure. In the application, alongitudinal direction of the cold plate 10 in top view is referred toas a “longitudinal direction X”, and a lateral direction thereof isreferred to as a “lateral direction Y”. A direction perpendicular to anupper surface of the cold plate 10 is referred to as a “perpendiculardirection Z”.

In the application, a “parallel direction” includes a substantiallyparallel direction. In the application, a “perpendicular direction”includes a substantially perpendicular direction.

A cooling apparatus according to an example embodiment of the presentdisclosure is described. FIGS. 1 and 2 are respectively a topperspective view and a bottom perspective view of a cooling apparatus 1according to an example embodiment of the present disclosure. FIG. 3 isa top view of the cooling apparatus 1, and FIG. 4 is a sectionalperspective view taken along line A-A in FIG. 3. FIG. 5 is a sectionalview taken along line B-B in FIG. 3.

In FIG. 2, a first refrigerant channel 11, a recessed portion 13 f, aninlet 13 a, an outlet 13 b, an ejection tube 10 h, and a suction tube 10g, which cannot be viewed from the outside of the cooling apparatus 1,are indicated by broken lines. In FIG. 3, the outlet 13 b, an upper wallthrough-hole 13 c, a first tank through-hole 41 a, and a second tankthrough-hole 42 a, which cannot be viewed from the outside of thecooling apparatus 1, are indicated by broken lines.

The cooling apparatus 1 includes the cold plate 10, the radiator 20, afirst tank 41, a second tank 42, and a pump 30. The radiator 20, thefirst tank 41, and the second tank 42 are disposed on the cold plate 10.The lower surfaces of the radiator 20, the first tank 41, and the secondtank 42 are in contact with the upper surface of the cold plate 10. Thepump 30 is disposed adjacently to a side of the cold plate 10.Accordingly, the cold plate 10, the radiator 20, the pump 30, the firsttank 41, and the second tank 42 are formed into a single unit to reducethe size of the entire cooling apparatus 1, thereby improving theperformance of handling the entire cooling apparatus 1.

The cold plate 10, the radiator 20, and the pump 30 are directlyconnected, which reduces the number of joint members, such as pipes.This further reduces the size of the cooling apparatus 1. Thus, it iseasy to mount the cooling apparatus 1 to a machine. The cold plate 10,the radiator 20, and the pump 30 may be coupled in an area on the coldplate 10 using shortened pipes or the like.

The cold plate 10 is composed of metal with high thermal conductivity,such as copper or aluminum, and has a bottom wall 12 and an upper wall13. In this example embodiment, the cold plate 10 is rectangular in topview. In other words, the bottom wall 12 and the upper wall 13 are inthe form of plates extending in the horizontal direction in top view.Although the bottom wall 12 and the upper wall 13 of this exampleembodiment are rectangular in top view, this is given for mereillustrative purposes. For example, the bottom wall 12 and the upperwall 13 may be polygonal or circular in top view. The lower surface ofthe bottom wall 12 is in contact with a heating component H (see FIG.4).

A notch 10 d is formed by bending a short side of the cold plate 10. Theside and the downside of the notch 10 d are open, and the upside of thenotch 10 d is closed. In other words, the upside of the notch 10 d iscovered with the upper wall 13.

The notch 10 d houses the pump 30, and the lower surface of the upperwall 13 and the upper surface of the pump 30 face each other.Accordingly, the size of the entire cooling apparatus 1 is reduced inthe up-down direction. The outer side of the pump 30 is located insidethe open end of the side of the notch 10 d. This further reduces thesize of the entire cooling apparatus 1. Thus, the outer side of the pump30 is prevented from coming into contact with a member disposed aroundthe heating component H when the heating component H is brought intocontact with the lower surface of the cold plate 10. Although in thisexample embodiment the outer side of the pump 30 is positioned insidethe open end of the side of the notch 10 d, it is sufficient that atleast part of the pump 30 is disposed in the notch 10 d to reduce thesize of the entire cooling apparatus 1.

The lower end of the pump 30 is disposed above the lower surface of thecold plate 10. This prevents the lower end of the pump 30 from cominginto contact with a mounting surface of the heating component H, whenthe heating component H is brought into contact with the cold plate 10,and prevents a clearance formed between the cold plate 10 and theheating component H. Thus, the heat generated from the heating componentH is efficiently transferred to the bottom wall 12 of the cold plate 10.

The cold plate 10 has the first refrigerant channel 11, the suction tube10 g, and the ejection tube 10 h through which the refrigerant flows.

The first refrigerant channel 11 is formed in an inner space enclosed bythe bottom wall 12, the upper wall 13, and a side wall 13 i. The sidewall 13 i is provided outside the recessed portion 13 f formed upwardfrom the lower surface of the upper wall 13. The recessed portion 13 fis formed by, for example, cutting the upper wall 13. The upper wall 13and the side wall 13 i may be formed of different members.

The first refrigerant channel 11 houses a plurality of parallel blades12 a. The upper wall 13 has an outlet 13 b passing through the upperwall 13 in the up-down direction and an upper wall through-hole 13 cpassing there the upper wall 13 in the up-down direction (see FIG. 3).The side wall 13 i has an inlet 13 a that opens to the first refrigerantchannel 11 (see FIG. 5). The refrigerant flowing into the firstrefrigerant channel 11 through the inlet 13 a flows out of the firstrefrigerant channel 11 through the outlet 13 b. In this exampleembodiment, the refrigerant is liquid, for example, an anti-freezesolution (such as an ethylene glycol aqueous solution or a propyleneglycol aqueous solution), pure water, or others.

One end of the suction tube 10 g opens to the notch 10 d on the side ofthe cold plate 10. The other end of the suction tube 10 g extendslinearly in the lateral direction Y to communicate with the upper wallthrough-hole 13 c (see FIG. 2).

One end of ejection tube 10 h opens to the notch 10 d on the side of thecold plate 10. The ejection tube 10 h extends in the lateral direction Yand bends at the other end in the longitudinal direction X tocommunicate with the inlet 13 a (see FIG. 2). The suction tube 10 g andthe ejection tube 10 h are respectively coupled to a suction port 31 aand an ejection port 31 b of the pump 30 (described later). The suctiontube 10 g and the ejection tube 10 h are described in detail below.

The pump 30 is a cascade pump and includes a refrigerant channel 31 d ina rectangular casing 31 (see FIG. 4). The channel 31 d houses animpeller (not illustrated) supported so as to be rotatable about thecentral axis extending in the up-down direction. The impeller is coupledto the rotation shaft of a motor (not illustrated).

The pump 30 has the suction port 31 a for sucking the refrigerant andthe ejection port 31 b for ejecting the refrigerant to the outside.Specifically, the casing 31 has the suction port 31 a and the ejectionport 31 b on the same side (see FIGS. 2 and 6). The suction port 31 aand the ejection port 31 b protrude outward from the side of the casing31. The suction port 31 a is coupled to the suction tube 10 g, and theejection port 31 b is coupled to the ejection tube 10 h. The impeller isrotated by driving the motor, so that the refrigerant flowing into thecasing 31 through the suction port 31 a is ejected through the ejectionport 31 b. In this example embodiment, the suction port 31 a and theejection port 31 b extend in a direction perpendicular to pipes 23.

The refrigerant ejected from the ejection port 31 b passes through theejection tube 10 h into the first refrigerant channel 11 via the inlet13 a. The first refrigerant channel 11 is coupled to the ejection port31 b, and the second refrigerant channel 22 is coupled to the suctionport 31 a via the second tank 42. Thus, the refrigerant cooled throughthe second refrigerant channel 22 flows into the pump 30. This preventsthe heat from being transferred to an electronic component (notillustrated) mounted in the pump 30, thereby improving the reliabilityof the pump 30.

The radiator 20 includes a plurality of fins 21 and a plurality of pipes23. The fins 21 have a planar shape, rising upright from the uppersurface of the upper wall 13 and extending in the horizontal directionof the cold plate 10. In this example embodiment, the plurality of fins21 extend in the lateral direction Y of the cold plate 10. The fins 21are arrayed at regular intervals in the longitudinal direction X of thecold plate 10.

The lower ends of the fins 21 are in contact with the upper surface ofthe upper wall 13. This increases the thermal conductivity from theupper wall 13 to the fins 21. The fins 21 and the upper wall 13 may beseparate members or the same member. In this example embodiment, thefins 21 are members separate from the upper wall 13. The lower ends ofthe fins 21 are joined to the upper surface of the upper wall 13, forexample, by welding.

If the fins 21 are the same members as the upper wall 13, the fins 21are formed, for example, by cutting the upper surface of the upper wall13.

If the fins 21 and the upper wall 13 are separate members, the fins 21are preferably made of metal with high thermal conductivity, such ascopper or aluminum, as the cold plate 10 is. When the fins 21 are madeof metal with high thermal conductivity, like the cold plate 10, theheat from the cold plate 10 can be efficiently transferred to the fins21.

The pipes 23 each form a second refrigerant channel 22, which is hollowand through which the refrigerant passes. The second refrigerantchannels 22 communicate with the first refrigerant channel 11.Specifically, one end of each second refrigerant channel 22 communicateswith one end of the first refrigerant channel 11 via the first tank 41.The other end of the second refrigerant channel 22 communicates with theother end of the first refrigerant channel 11 via the second tank 42 andthe pump 30.

The pipes 23 extend linearly in the longitudinal direction X of the coldplate 10. The pipes 23 have a flat cross section and are inclined in theY-Z plane with respect to the upper surface of the cold plate 10 (seeFIG. 5). The pipes 23 are each placed in a fin through-hole 24 providedin the plurality of fins and are fixed to the plurality of fins 21 bywelding. A direction in which the pipes 23 extend and a direction inwhich the fins 21 extend cross at right angles. In other words, in thisexample embodiment, the plurality of fins 21 extend in the lateraldirection Y, and the pipes 23 extend in the longitudinal direction X.Directions in which the fins 21 and the pipes 23 extend are not limitedto the directions described above. For example, the pipes 23 may bedisposed at an angle with respect to the direction in which the fins 21extend.

One end of each pipe 23 is coupled to the first tank 41, and the otherend of each pipe 23 is coupled to the second tank 42. The first tank 41and the second tank 42 are opposed in the direction in which the pipes23 extend. Accordingly, the refrigerant smoothly flows linearly from thefirst tank 41 to the second tank 42 through the pipes 23.

The first tank 41 and the second tank 42 are disposed parallel to thearray of the fins 21. This allows more fins 21 to be disposed betweenthe first tank 41 and the second tank 42 at predetermined intervals. Asa result, the surface area of the entire fins 21 increases, therebyimproving the cooling performance of the radiator 20. Furthermore, it iseasy to connect the pipes 23, the first tank 41, and the second tank 42.

The pipes 23 pass through the sides of the first tank 41 and the secondtank 42 and are directly coupled to the first tank 41 and the secondtank 42 (see FIG. 4). This reduces the number of components of thecooling apparatus 1 and increases the lengths of the pipes 23 in thelongitudinal direction X to more efficiently cool the refrigerant.

As illustrated in FIG. 5, the pipes 23 in this example embodiment aredisposed in three arrays in the horizontal direction and in three arraysin the up-down direction. Thus, nine pipes 23 in total are connected inparallel via the first tank 41 and the second tank 42 (see FIG. 5).Accordingly, heat is transferred from the pipes 23 to the plurality offins 21, thereby efficiently cooling the refrigerant, while suppressingan increase in the size of the cooling apparatus 1. The number of thepipes is not limited to nine and may be eight or less, or ten or more.The plurality of pipes 23 may not be disposed at regular intervals andmay be disposed at different positions in the up-down direction.

The first tank 41 and the second tank 42 are rectangular cuboids andrespectively have a first tank through-hole 41 a and a second tankthrough-hole 42 a in the lower surfaces passing through the first tank41 and the second tank 42 in the up-down direction.

The second tank 42 is disposed above the notch 10 d. This allows thepump 30 in the notch 10 d and the second tank 42 to be disposed close toeach other. Accordingly, the number of components, such as a pipecoupling the pump 30 and the second tank 42 is reduced, thereby reducingthe size of the cooling apparatus 1.

Disposing the second tank through-hole 42 a in the lower surface of thesecond tank 42 further reduces the number of components, such as a pipecoupling the pump 30 and the second tank 42. The first tank through-hole41 a is aligned and communicates with the outlet 13 b of the upper wall13 in the up-down direction (see FIG. 3). The second tank through-hole42 a is aligned and communicates with an end of the upper wallthrough-hole 13 c communicating with the suction tube 10 g in theup-down direction (see FIG. 3).

FIG. 6 is a bottom view of the upper wall 13 and illustrates a state inwhich the pump 30 is disposed. FIG. 7 is a top view of the bottom wall12. In FIG. 7, the one-dot chain line indicates the outlet 13 b and therecessed portion 13 f of the upper wall 13.

Sides on the short side of the upper wall 13 and the bottom wall 12 arebent in top view to form an upper-wall notch 13 d and a bottom-wallnotch 12 d, respectively. The side and the lower side of the upper-wallnotch 13 d are open, and the upper side of the notch 10 d is closed. Theupper-wall notch 13 d and the bottom-wall notch 12 d form the notch 10 dof the cold plate 10.

Protrusions 13 e protruding downward are provided at the four corners ofthe lower surface of the upper-wall notch 13 d. The upper surface of thepump 30 is in contact with the lower surfaces of the protrusions 13 e.As a result, an interspace S is formed between the lower surface of theupper wall 13 and the upper surface of the pump 30 (see FIG. 1). Inother words, there is the interspace S between the lower surface of theupper wall 13 and the upper surface of the pump 30. This reducestransfer of the heat of the cold plate 10 to the pump 30 and preventsacceleration of heat generation of an electronic component (notillustrated) in the pump 20, thereby increasing the service life of thepump 20.

The lower surface of the upper wall 13 has a groove 13 g recessed upwardand a groove 13 h recessed upward. The upper surface of the bottom wall12 has a groove 12 g recessed downward and a groove 12 h recesseddownward. When the lower surface of the upper wall 13 and the uppersurface of the bottom wall 12 are joined in the up-down direction, thegroove 13 g and the groove 12 g face in the up-down direction to formthe suction tube 10 g, and the groove 13 h and the groove 12 h face inthe up-down direction to form the ejection tube 10 h.

In other words, the cold plate 10 includes the suction tube 10 g and theejection tube 10 h. The suction tube 10 g is formed of the groove 13 gand the groove 12 g facing in the up-down direction. The ejection tube10 h is formed of the groove 13 h and the groove 12 h facing in theup-down direction.

The suction port 31 a is held by the groove 13 g and the groove 12 g andis coupled to the suction tube 10 g. The ejection port 31 b is held bythe groove 13 h and the groove 12 h and is coupled to the ejection tube10 h.

Specifically, the inner surfaces of the groove 13 g and the groove 12 gand the outer surface of the suction port 31 a are brought into contactwith each other, and the outer surface of the suction port 31 a ispressed by the inner surfaces of the groove 13 g and the groove 12 gfrom above and below. Likewise, the inner surfaces of the groove 13 hand the groove 12 h and the outer surface of the ejection port 31 b arebrought into contact with each other, and the outer surface of theejection port 31 b is pressed by the inner surfaces of the groove 13 hand the groove 12 h from above and below. This makes it easy to couplethe suction port 31 a and the ejection port 31 b to the suction tube 10g and the ejection tube 10 h, respectively.

More specifically, the pump 30 is placed on the protrusions 13 e of theupper-wall notch 13 d, and the suction port 31 a and the ejection port31 b are respectively fit in the groove 13 g and the groove 13 h,thereafter, the lower surface of the upper wall 13 and the upper surfaceof the bottom wall 12 are joined together in the up-down direction whilethe grooves 12 g and 12 h are being pressed against the suction port 31a and the ejection port 31 b, respectively. Thus, the suction port 31 aand the ejection port 31 b are accurately positioned and easily coupledto the suction tube 10 g and the ejection tube 10 h, respectively.

The blades 12 a are provided on the upper surface of the bottom wall 12.The blades 12 a extend in the longitudinal direction X of the cold plate10 and disposed parallel to each other at regular intervals in thelateral direction Y. A clearance is formed in the up-down directionbetween the upper ends of the blades 12 a and the lower surface of theupper wall 13 (see FIG. 5). The upper ends of the blades 12 a may be incontact with the lower surface of the upper wall 13.

The refrigerant flowing into the first refrigerant channel 11 throughthe inlet 13 a spreads in the lateral direction Y on the bottom wall 12to flow between the plurality of blades 12 a. The refrigerant flowingbetween the plurality of blades 12 a spreads over the first refrigerantchannel 11 and flows out through the outlet 13 b. Accordingly, theentire lower surface of the cold plate 10 is cooled by the refrigerant.

The lower surface of the bottom wall 12 is in contact with the heatingcomponent H (see FIG. 4). The heating component H is preferably disposedon the lower surface of the bottom wall 12 facing the first refrigerantchannel 11 in the up-down direction. Opposing the heating component Hand the first refrigerant channel 11 in the up-down direction allows theheat generated from the heating component H to be efficientlytransferred to the refrigerant flowing in the first refrigerant channel11.

It is more preferable that the heating component H be disposed below thearea of the blades 12 a. In other words, the heating component H islocated within the width of the blades 12 a in the longitudinaldirection X in which the blades 12 a extend and within the width of thearray of the blades 12 a in the lateral direction Y in which the blades12 a are arrayed. Disposing the heating component H at a positionoverlapping the area allows the heating component H to be cooled moreefficiently.

More preferably, the heating component H is disposed at a positionoverlapping a line connecting the inlet 13 a and the outlet 13 b. Therefrigerant circulating in the cooling apparatus 1 is cooled by theradiator 20 around the line connecting the inlet 13 a and the outlet 13b. Accordingly, disposing the heating component H on this line allowsthe heating component H to be cooled more efficiently.

The heating component H to be cooled, such as a central processing unit(CPU), is brought into contact with the lower surface of the bottom wall12 of the cold plate 10, and the pump 30 is driven. This causes therefrigerant to circulate through the first refrigerant channel 11, thefirst tank 41, the second refrigerant channel 22, and the second tank 42in this order. The heat of the heating component H is transferred to thebottom wall 12 of the cold plate 10. The heat transferred to the bottomwall 12 is transferred to the fins 21 through the upper wall 13 and viathe refrigerant flowing through the first refrigerant channel 11 and thesecond refrigerant channel 22. Thus, heat is radiated through the fins21, thereby preventing an increase in the temperature of the heatingcomponent H.

Disposing a cooling fan (not illustrated) on a side of the radiator 20and sending cooling air in the direction in which the fins 21 extend(the lateral direction Y) promote heat radiation from the fins 21,thereby further improving the cooling performance of the radiator 20.

The above example embodiments are given for mere illustrative purposes.The configurations of the example embodiments may be changed asappropriate without departing from the technical spirit of the presentdisclosure. The example embodiments may be combined within the possiblescope.

Although the above example embodiments use the cascade pump 30, adiaphragm pump or a centrifugal pump may be used.

The motor of the present disclosure may be used in a cooling apparatusthat cools an electronic component, such as a microcomputer.

While example embodiments of the present disclosure have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. The scope of the presentdisclosure, therefore, is to be determined solely by the followingclaims.

What is claimed is:
 1. A cooling apparatus comprising: a cold plateincluding a first refrigerant channel through which refrigerant flows,the cold plate extending in a first direction and a second directionperpendicular to the first direction; and a pump to circulate therefrigerant; wherein the cold plate includes a bottom wall and an upperwall; a lower surface of the bottom wall is in contact with a heatingelement; the upper wall is in contact with the bottom wall in a thirddirection perpendicular to the first direction and the second direction;a lower surface of the upper wall and an upper surface of the pumpdirectly oppose each other in the third direction; and a lower surfaceof the pump is exposed to an outside of the cooling apparatus in thethird direction.
 2. The cooling apparatus according to claim 1, whereina side wall of the pump is exposed to the outside of the coolingapparatus in at least one of the first direction and the seconddirection.
 3. The cooling apparatus according to claim 2, wherein theside wall of the pump is exposed to the outside of the cooling apparatusin the first direction.
 4. The cooling apparatus according to claim 2,wherein the side wall of the pump is exposed to the outside of thecooling apparatus in the first direction and the second direction. 5.The cooling apparatus according to claim 2, wherein the side wall of thepump is exposed to the outside of the cooling apparatus in the seconddirection.
 6. The cooling apparatus according to claim 1, wherein arefrigerant space is between the lower surface of the upper wall and theupper surface of the bottom wall.
 7. The cooling apparatus according toclaim 6, wherein the refrigerant space includes refrigerant flowingtherein.
 8. The cooling apparatus according to claim 1, wherein thebottom wall of the cold plate includes a notch including a bend in aside of the cold plate in the first direction.
 9. The cooling apparatusaccording to claim 8, wherein at least a portion of the pump is locatedin the notch.
 10. The cooling apparatus according to claim 9, wherein anouter side of the pump is located inside an open end on a side of thenotch.